System and method for monitoring remote devices with a dual-mode wireless communication protocol

ABSTRACT

The present invention is generally directed to systems and device for monitoring remote device with a wireless, dual-mode communication protocol. As such, a representative embodiment is a system for monitoring and controlling remote devices. The system includes a first- and a second remote device; and a first and a second wireless transceiver integrated with the respective remote devices. The wireless transceivers are configured to communicate with at least one of a spread-spectrum communication protocol and a fixed-frequency communication protocol.

BACKGROUND SECTION

Prior art monitoring and controlling systems for various applications,such as automated meter reading, prognostics, vending machines, and firealarm and sprinkler systems utilize various communication protocols.Generally, these protocols utilize wireless RF communications eitherbetween transceivers or between a plurality of transceivers and a remoteinterrogator. The remote interrogator may then be coupled to a wide areanetwork (WAN) which enables access to the transceivers by backendservers, workstations, etc.

In some instances, the RF transceivers may utilize a single-channel,substantially low-power communications protocol and, thus, have alimited range. The low-power applications are advantageous in certainremote applications, where a constant power supply is not available. Forexample, a transceiver coupled to a water meter cannot tap into anylocal power at the water meter, because typically there is no power. Inthis case, a battery is typically used. In order to maximize the lifespan of the battery, low-power transmissions are used. Low-powertransmissions may also be advantageous because at certain frequencybands, a license from the Federal Communication Commission (FCC) is notrequired. The FCC requires certain devices to be licensed and/or complywith certain provisions if the devices radiate enough power within agiven frequency spectrum over a given period.

Unfortunately, there are drawbacks to a low-power, single-channelcommunication protocol. In particular, the range of communication isdirectly proportional to the level of radiated power. Therefore, lowpower implies shorter communication range. Shorter communication rangegenerally requires more infra-structure in a wireless system.Furthermore, single-channel communications (e.g., communications withinone frequency channel, or on one carrier frequency) can be a problem ifthere is other electromagnetic radiation in a given area. Interferencefrom other devices may cause noise at or near the specific singlechannel in which the RF transceivers are attempting to communicate, thusmaking communication unreliable, if not unfeasible.

Considering these drawbacks, it would be desirable to have acommunication protocol that overcomes the disadvantages illustratedabove. Furthermore, it would be advantageous for a systems provider forthe communication devices (i.e., the RF transceivers and gateways) to becompatible with both communications protocols so that a communicationupgrade would not require existing devices to be replaced. Instead theexisting devices could be upgraded remotely through the system.

SUMMARY

Various embodiments of a dual-mode communication protocol, andcorresponding systems, devices, methods, and computer programs, areprovided. One embodiment is a system for monitoring and controllingremote devices. The system includes a first and a second remote device;and a first and a second wireless transceiver integrated with saidrespective remote devices. The wireless transceivers are configured tocommunicate with at least one of a spread-spectrum communicationprotocol and a fixed-frequency communication protocol.

Another embodiment is a system for monitoring the utility consumptionmeasured by a plurality of utility meters. The system includes aplurality of utility meters and a network of wireless RF transceiversfor communicating utility consumption data. The network of wireless RFtransceivers is comprised of at least a first dual-mode transceiver, atleast a first fixed-frequency transceiver, and at least a firstspread-spectrum transceiver. The system further includes at least afirst gateway in communication with each wireless RF transceiver eitherdirectly or via other wireless RF transceivers. The at least firstgateway relays data from the network of wireless RF transceivers to aback-end system.

Yet another embodiment is a wireless transceiver used within a systemfor monitoring remote devices. The wireless transceiver includes an RFtransceiver for communicating in at least one of a spread-spectrumcommunication protocol and a fixed-frequency communication protocol anda data controller coupled to the RF transceiver for processing data tobe either transmitted by or received from the RF transceiver. Thewireless transceiver also includes memory for storing various logic tobe performed by the data controller and the RF transceiver forcommunicating in at least one of the communication protocols.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification, illustrate several aspects of the present invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a block diagram illustrating an embodiment of a dual-modemonitoring/control system.

FIG. 2 is a block diagram illustrating the functional components of anembodiment of a dual-mode transceiver of the system of FIG. 1.

FIG. 3 is an illustration of an exemplary frequency band implemented inthe system of FIG. 1.

FIG. 4A is a data structure illustrating an embodiment of afixed-frequency communication packet for the system of FIG. 1.

FIG. 4B is a data structure illustrating an embodiment of aspread-spectrum communication packet for the system of FIG. 1.

FIG. 5 is a flow chart illustrating an embodiment of a method fortransmitting in a dual-mode communication protocol.

FIG. 6 is a flow chart illustrating an embodiment of a method fortransmitting in a spread-spectrum communication protocol.

FIG. 7 is a flow chart illustrating an embodiment of a method forreceiving in the dual-mode communication protocol.

FIG. 8 is a flow chart illustrating an embodiment of a method forreceiving in the spread-spectrum communication protocol.

DETAILED DESCRIPTION

Embodiments illustrated in further detail below illustrate varioussystems, methods, devices, and programs for communicating in a dual-modecommunication protocol. A first communication protocol may generally beconsidered a fixed-frequency communication protocol and a secondcommunication protocol may generally be considered a spread-spectrumcommunication protocol.

An embodiment of a transceiver communicating in a fixed-frequencycommunication protocol is generally configured to communicate acommunication packet at a single frequency channel, with a firstmodulation scheme, at a given radiating power level.

An embodiment of a transceiver communicating in a spread-spectrumcommunication protocol is generally configured to communicate a firstportion of a communication packet at a first frequency channel, and thencommunicate a second portion of the communication packet at a secondfrequency channel. The spread-spectrum communication protocol may employa second modulation scheme, at a given radiating power level.

An embodiment of a transceiver communicating in the dual-modecommunication protocol can generally communicate in both communicationprotocols. By providing for both communication protocols, thedisadvantages of utilizing one singular protocol may be avoided. Theaccompanied figures and description illustrate embodiments of thedual-mode communication protocol in further detail.

Turning now to FIG. 1, illustrated is a block diagram of an embodimentof a dual-mode monitoring/control system 1. Dual-mode system 1 comprisesone or more external devices to be monitored and/or controlled (e.g.,sensor/actuators 10) as illustrated in FIG. 1. Each sensor/actuator maybe integrated with a transceiver 30, 31, or 32. The transceivers 30-32are preferably RF (radio frequency) transceivers that are relativelysmall in size. Depending on the communication mode utilized, thetransceivers 30-32 transmit either a relatively low-power RF signal, ora higher-power RF signal. As a result, in some applications, thetransmission range of a given transceiver may be relatively limited.Although the transceivers 30-32 are depicted without a user interfacesuch as a keypad, in certain embodiments, the transceivers 30-32 may beconfigured with user selectable buttons or an alphanumeric keypad. Thetransceivers 30-32 may be electrically interfaced with the device to bemonitored and/or controlled, such as a smoke detector, a thermostat, asecurity system, etc., where external buttons are not needed.

Dual-mode system 1 also includes a plurality of stand-alone transceivers33-35, which may be fixed or mobile. Each stand-alone transceiver 33-35and each of the integrated transceivers 30-32 may be configured toreceive an incoming RF transmission (transmitted by a remotetransceiver) and to transmit an outgoing signal. The transceiversdepicted in FIG. 1 may include different functionality depending onwhether the transceiver communicates in a fixed-frequency communicationmode, a spread-spectrum communication mode, or both. These communicationmodes, or protocols, will be discussed in further detail in subsequentfigures. All transceivers may include the hardware and/or software tocommunicate in either of the protocols, but may be programmed orconfigured to communicate in only one or the other, or both,

Fixed-frequency transceiver 30 is an integrated transceiver that isconfigured to communicate only with the fixed-frequency communicationprotocol. In general, the fixed-frequency communication protocol is anyprotocol in which a packet or frame of data is communicated within asingle frequency channel. Transceiver 35 is the stand-alone counterpartto transceiver 30. A fixed-frequency communication link is illustratedin FIG. 1 with a thin communication bolt designated with numeral 40.

Spread-spectrum transceiver 31 is an integrated transceiver that isconfigured to communicate only with the spread-spectrum communicationprotocol. The spread-spectrum communication protocol will be discussedin further detail, but in short, is a protocol that facilitatesfrequency-channel hopping within a given frequency band. Transceiver 34is the stand-alone counterpart to transceiver 31. A spread-spectrumcommunication link is denoted in FIG. 1 with a wide communication boltand given numeral 45.

Dual-mode transceiver 32 is an integrated transceiver that is configuredto communicate with either of the two aforementioned protocols.Transceiver 33 is the stand-alone counterpart to the dual-modetransceiver 32.

Notably, each transceiver can communicate only with another transceiverconfigured for similar protocols. In other words, a fixed-frequencytransceiver 30, 35 cannot communicate with a spread-spectrum transceiver31, 34. This, however, can be reasonably obviated by deploying dual-modetransceivers 32, 33 into the wireless infrastructure.

The specifics of a fixed-frequency communication 40 will be discussed infurther detail in FIG. 4A and the specifics of a spread-spectrumcommunication 45 will be discussed in further detail in FIG. 4B. Bothcommunications, however, are preferably wireless, RF transmissions, andmore preferably, in the 902-928 MHz frequency range. Although this ispreferable, in other embodiments, alternative frequency ranges may beemployed. Furthermore, each communication may be transmitted over aconductive wire, fiber optic cable, or other transmission media.

The internal architecture of a transceiver 30-32 integrated with asensor/actuator 10 and a stand-alone transceiver 33-35 will be discussedin more detail in connection with FIG. 2. It will be appreciated bythose skilled in the art that integrated transceivers 30-32 can bereplaced by RF transmitters (not shown) for client specific applicationsthat only require data collection only.

Local gateways 15 are configured and disposed to receive remote datatransmissions from the various stand-alone transceivers 33-35 orintegrated transceivers 30-32 having an RF signal output levelsufficient to adequately transmit a formatted data signal to thegateways. Local gateways 15 can communicate in either of the twoaforementioned communication protocols. Thus, for the purpose of thisdocument, they will be considered dual-mode gateways 15. In otherembodiments, local gateways 15 may be capable of communicating in onlyone of the aforementioned protocols.

Local gateways 15 analyze the transmissions received, convert thetransmissions into TCP/IP format (or other protocol), and furthercommunicate the remote data signal transmissions to back-end system 21via WAN 20. In this regard, and as will be further described below,local gateways 15 may communicate information, service requests, controlsignals, etc., to integrated transceivers 30-32 from server 25, laptopcomputer 28, and workstation 27 across WAN 20. Server 25 can be furthernetworked with database server 26 to record client specific data. Server25, laptop computer 28, and workstation 27 are capable of remotelycontrolling and/or configuring various functions of the transceivers.For instance, server 26 is capable of remotely controlling thecommunication protocol in which each transceiver can communicate. Thiscan be accomplished by sending a downstream control signal and/or bysending a software/firmware upgrade downstream.

It will be appreciated by those skilled in the art that if an integratedtransceiver (either of 30-32) is located sufficiently close to dual-modelocal gateways 15 to receive RF data signals, the RF data signal neednot be processed and repeated through stand-alone transceivers 33-35. Itwill be further appreciated that the system 1 may be used in a varietyof environments. In one embodiment, system 1 may be employed to monitorand record utility usage of residential and industrial customers. Inanother embodiment, system 1 may be configured for the transfer ofvehicle diagnostics from an automobile via an RF transceiver integratedwith the vehicle diagnostics bus to a local transceiver that furthertransmits the vehicle information through a local gateway onto a WAN.

Generally, transceivers 30-32 may have similar construction(particularly with regard to their internal electronics) whereappropriate, which provides a cost-effective implementation at thesystem level. Alternatively, fixed-frequency transceiver 30 may includesome different internal electronics then spread-spectrum transceiver 31.Furthermore, dual-mode transceiver 32 may include different internalelectronics as transceivers 30 and 31. Stand-alone transceivers 33-35may include similar communication components as their integratedcounterparts. The necessary hardware and software to integrate with asensor/actuator 10 may, however, be excluded.

As illustrated in FIG. 1, stand-alone transceivers 33-35 are disposed toprovide adequate coverage in a desired geographic area (e.g., anindustrial plant or community), which is based on the particular systemapplication. Preferably, stand-alone transceivers 33-35 may be dispersedso that at least one stand-alone transceiver will pick up a transmissionfrom a given integrated transceiver 30-32. However, in certaininstances, two or more stand-alone transceivers may pick up a singletransmission. Thus, local gateways 15 may receive multiple versions ofthe same data transmission signal from an integrated transceiver, butfrom different stand-alone transceivers. Local gateways 15 may utilizethis information to triangulate, or otherwise more particularly assessthe location from which the transmission is originating. Due to thetransmitting device identification that is incorporated into thetransmitted signal, duplicative transmissions (e.g., transmissionsduplicated to more than one gateway, or to the same gateway, more thanonce) may be ignored or otherwise appropriately handled.

Integrated transceivers 30-32 may be implemented in a variety ofdevices. For example, integrated transceivers 30-32 may be disposedwithin automobiles, a rainfall gauge, a parking lot access gate, andutility meters to monitor vehicle diagnostics, total rainfall andsprinkler supplied water, access gate position, and utility consumption,to name a few. The advantage of integrating a transceiver, as opposed toa one-way transmitter, into a monitoring device relates to the abilityof the transceiver to receive incoming control signals, as opposed tomerely transmitting data signals. Significantly, local gateways 15 maycommunicate with all system transceivers. Since local gateways 15 areintegrated with WAN 20, server 25 can host application specific softwarethat is typically hosted in an application specific local controller. Offurther significance, the data monitoring and control devices need notbe disposed in a permanent location. Provided the monitoring and controldevices remain within signal range of a system compatible transceiver,which is within signal range of local gateway 15 interconnected throughone or more transceiver networks to server 25. In this regard, smallapplication specific transmitters compatible with system 1 can be wornor carried about one's person or coupled to an asset to be tracked andmonitored.

In one embodiment, server 25 collects, formats, and stores clientspecific data from each of the integrated transceivers 30-32 for laterretrieval or access from workstation 27 or laptop 28. In this regard,workstation 27 or laptop 28 can be used to access the stored informationthrough a Web browser in a manner that is well known in the art. Inanother embodiment, server 25 may perform the additional functions ofhosting application specific control system functions and replacing thelocal controller by generating required control signals for appropriatedistribution via WAN 20 and local gateways 15 to the systemsensors/actuators. In a third embodiment, clients may elect forproprietary reasons to host control applications on their own WANconnected workstation. In this regard, database 26 and server 25 may actsolely as a data collection and reporting device with client workstation27 generating control signals for the system 1.

It will be appreciated by those skilled in the art that the informationcommunicated by the transceivers 30-35 may be further integrated withother data transmission protocols for transmission acrosstelecommunications and computer networks other than the Internet. Inaddition, it should be further appreciated that telecommunications andcomputer networks other than the Internet can function as a transmissionpath between the transceivers, the local gateways, and the centralserver. For example, an integrated transceiver may communicate with astand-alone transceiver in a RF communication scheme. The stand-alonetransceiver may communicate with the gateway 15 in a cellularcommunication scheme, such as GSM or PCS. The gateway 15 may communicatewith the back-end system 21 via satellite, POTS, or the Internet.

Reference is now made to FIG. 2, which is a block diagram thatillustrates functional components of an embodiment of a dual-modetransceiver 32, 33. Dual-mode transceiver 32, 33 may communicate withanother transceiver 30, 32, 33, and 35 or gateway 15 with thefixed-frequency communication protocol, or may communicate with anothertransceiver 31-34 or gateway 15 with the spread-spectrum communicationprotocol.

The integrated dual-mode transceiver 32 is coupled to external devices10, for example, sensor 11 and actuator 12, by way of data interface 70.Data interface 70 is configured to receive electrical signals fromsensor 11 and provide electrical signals to actuator 12, and ultimatelyconvey such information to and from a data controller 50. In oneembodiment, data interface 70 may simply comprise an addressable portthat may be read by the data controller 50. Dual-mode transceiver 33 isa stand-alone transceiver, thus may not include the data interface 70for coupling to external components 10, such as sensor 11 and actuator12.

Data controller 50 is coupled to memory 100 which stores varioussoftware, firmware, and other logic. Further coupled with datacontroller 50 is an RF transceiver 80 which is used to convertinformation received from data controller 50 in digital electronic forminto a format, frequency, and voltage level suitable for transmissionfrom antenna 60 via an RF transmission medium. RF transceiver 80 alsoconverts a received electromagnetic signal from antenna 60 into digitalelectronic form for data controller 50 to process.

Data controller 50 may be considered a micro-controller ormicro-processor and, as such, is configured for performing the dataprocessing for the transceiver 32, 33. Data controller 50 is configuredto perform operations as directed by firmware 102 stored in memory 100.These operations include data formatting for communication in both modesof communication, as well as data formatting for communication withsensor 11 and actuator 12 (if so equipped).

RF transceiver 80 of dual-mode transceiver 32, 33 may include distinctchipsets for each communication protocol: a fixed-frequencycommunication protocol chipset (FF chipset) 81 and a spread-spectrumcommunication protocol chipset (SS chipset 82). Chipsets 81 and 82include the necessary components for transmitting and receiving in theparticular communication protocols. For example, FF chipset 81 includesthe components for communicating in a first modulation scheme, at agiven power level, and in a particular frequency band in accordance withthe fixed-frequency communication protocol. SS chipset 82 includes thecomponents for communicating in a second modulation scheme, at a givenpower level, and in another particular frequency band in accordance withthe spread-spectrum communication protocol. In other embodiments, thechipsets may be fully integrated.

Fixed-frequency transceivers 30 and 35 may differ from dual-modetransceivers 32 and 33 because they may not include SS chipset 82.Alternatively, data controller 50 for fixed-frequency transceivers 30and 35 may not be programmed, by firmware 102, for communicating in thespread-spectrum communication protocol. As will be discussed shortly,certain modules of memory 100 which are included in dual-modetransceivers 32 and 35 may not be included in fixed-frequencytransceivers 30 and 35.

Likewise, spread-spectrum transceivers 31 and 34 may differ fromdual-mode transceivers 32 and 33 because they may not include FF chipset81. Alternatively, data controller 50 for the spread-spectrumtransceivers 31 and 34 may not be programmed, by firmware 102, tocommunicate in the fixed-frequency communication protocol.

Memory 100 can include any one or combination of volatile memoryelements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM,etc.)) and nonvolatile memory elements (e.g., ROM, hard drive, tape,CDROM, etc.). Moreover, the memory 100 may incorporate electronic,magnetic, optical, and/or other types of storage media. Memory 100 canhave a distributed architecture, where various components are situatedremote from one another, but can be accessed by the data controller 50.Modules included in the memory 100 of a dual-mode transceiver 32 and 33are a data channel index table 103, an acquisition channels table 105, afixed-frequency channels table 106, a receiver (Rx) address table 104,firmware 102, RAM 101, and a transceiver identification (Tx ID) 107.

The data channel index table 103 is utilized for communication in thespread-spectrum communication protocol. The contents of the data channelindex table 103 will become clearer as the spread-spectrum communicationprotocol is laid out in subsequent figures. In short, the data channelindex table 103 includes a list of data channel frequencies in which adata portion of a communication packet may be communicated. Each datachannel is given an index that RF transceiver 80 will recognize, andfurthermore can be communicated in a preamble of a communication packet.A receiving transceiver 31-34 or gateway 15 will need to recover thedata channel index from the preamble to properly receive the remainderof a communication packet. In the preferred embodiment, there are 40frequency channels dedicated for data communication each channeldesignated by a unique data channel index. One will appreciate that thenumber of channels is not relevant. Accordingly, in other embodiments,the number of channels may vary.

The acquisition channels table 105 is utilized for communication in thespread-spectrum communication protocol. The acquisition channels table105 includes a list of frequency channels designated for synchronizingcommunication with another transceiver and for communicating a preambleof a communication packet. In the preferred embodiment there are tendesignated acquisition channels, although this number can vary. Anunderstanding of the acquisition channels table 105 will become clearerupon further explanation of the spread-spectrum communication protocol.

The fixed-frequency channels table 106 is utilized for communication inthe fixed-frequency communication protocol. The fixed-frequency channelstable 106 includes a list of frequency channels designated forsynchronizing communication and subsequently communicating the dataportion of a communication packet. In the preferred embodiment, thereare eight fixed-frequency channels. An understanding of thefixed-frequency channels table 106 and its associated fixed-frequencychannels will become clearer upon further explanation of the dual-modecommunication protocol.

Each transceiver is configured to have a unique identification code 107(e.g., transceiver identification number—Tx ID), that uniquelyidentifies the transceiver to the functional blocks of control system 1(see FIG. 1). This transceiver identification number 107 may beelectrically programmable, and implemented in the form of, for example,an EPROM. Alternatively, the transceiver identification number 107 maybe set/configured through a series of DIP switches, or stored in RAM.Alternative methods of setting and configuring the transceiveridentification number 107 may be implemented.

Rx address table 104 is generally a look-up table of transceiveridentification numbers (Tx IDs), or addresses, of other transceivers ina given network in the system 1 and is called upon when preparing acommunication packet to be transmitted. Each communication packettransmitted by any transceiver 30-35, or gateway 15, is destined for aparticular transceiver as designated by the transceiver identificationnumber 107 embedded within the communication packet for eithercommunication protocol (to be illustrated in FIG. 4). As a transceiverreceives various packets, it can distinguish, by the transceiveridentification number embedded in the communication packet, whether thatpacket is destined for that transceiver. Otherwise, the transceiver maydisregard the packet and/or relay the packet along to anothertransceiver. The specifics of how a communication packet is processedupon reception, including relaying the packet, is generally beyond thescope of the present invention.

The Rx address table 104 may also include more information about othertransceivers, such as the communication protocol with which the othertransceivers communicate. Furthermore, the desired modulation scheme(s)with which the other transceivers communicate as well as a necessaryradiating-power level. Importantly some or all of the contents of the Rxaddress table 104 can be updated remotely, for instance, by server 26.

Firmware 102 includes the logic for operating data controller 50 inaccordance with embodiments of the present invention. Logic configuredto perform operations as laid out in flow charts illustrated insubsequent figures is found in firmware 102, along with programminglogic for communicating with data interface 70 and its coupledcomponents 10. Other programming logic may be incorporated in thefirmware 102 as known by those of ordinary skill in the art, such aspower conservation sequences, power-up and power-down sequences, andoperating system upgrade sequences.

Sensor 11, in its simplest form, could be a two-state device such as asmoke alarm. Alternatively, the sensor 11 may output a continuous rangeof values to the data interface 70. If the signal output from the sensor11 is an analog signal, the data interface 70 may include ananalog-to-digital converter (not shown) to convert signals output to theactuator 12. Alternatively, a digital interface (communicating digitalsignals) may exist between the data interface 70 and each sensor 11. InFIG. 2, data interface 70 is shown with a single input from sensor 11.It is easy to envision a system that may include multiple sensor inputs.By way of example, a common home heating and cooling system might beintegrated with the present invention. The home heating system mayinclude multiple data interface inputs from multiple sensors. A homethermostat control connected with the home heating system could beintegrated with a sensor that reports the position of a manuallyadjusted temperature control (i.e., temperature set value), as well as,a sensor integrated with a thermostat to report an ambient temperature.The condition of related parameters can be input to data interface 70 aswell, including the condition of the system on/off switch, and theclimate control mode selected (i.e., heat, fan, or AC). In addition,depending upon the specific implementation, other system parameters maybe provided to data interface 70 as well.

The integration with an actuator 12 permits data interface 70 to applycontrol signals to a manual temperature control for the temperature setpoint, a climate control mode switch, and a system on/off switch. Inthis way, a remote workstation 27 or laptop 28 with WAN access (seeFIG. 1) could control a home heating system from a remote location.

The operation of an embodiment of transceiver 32, 33 is best illustratedin the flow charts of FIGS. 5-8. However, a brief explanation of theoperation should be made with reference to the particular componentsillustrated in the block diagram of FIG. 2. The dual-mode transceiver32, 33, as its name implies, can communicate in any one of two modes orprotocols: the fixed-frequency communication protocol and thespread-spectrum communication protocol.

When transmitting in the fixed-frequency communication protocol, datacontroller 50 will build a fixed-frequency communication packet(described in FIG. 4A) and pass that along to the RF transceiver 80 forcommunication. A communication packet is transmitted in thefixed-frequency communication protocol by transmitting at a dedicatedchannel, where the dedicated channel is one of the fixed-frequencychannels (as illustrated in FIG. 3). Preferably, the dedicated channelfor transmission is the center channel of the fixed-frequency band,which, in the case of FIG. 3, is the 916.5 MHz channel. Alternatively,building the fixed-frequency communication packet may involve queryingthe fixed-frequency channels table 106 to find the next fixed-frequencychannel in which to communicate. The selected frequency channel iscommunicated to the FF chipset 81 along with the communication packet.In another alternative, the FF chipset 81 may be configured to cyclethrough the designated fixed-frequency channels without having toreceive an index or pointer to a channel from the memory 100. In thisalternative embodiment, the fixed-frequency channel table 106 may beexcluded from the memory 100 and stored in memory integrated in with theFF chipset 81. The payload portion of the communication packet ispopulated with the relevant information to be communicated, which mayinclude information received from the data interface 70. The datacontroller 50 may query the Rx address table 104 to make sure thedestined transceiver can communicate in the fixed-frequencycommunication mode. After the packet is assembled it is passed along tothe transceiver 80 for transmission.

FF chipset may receive in the fixed-frequency communication mode bycycling through the fixed-frequency channels to look for a carriersignal. Once found and synchronized, the packet communicated at thatcarrier channel is received and passed along to the data controller 50for processing. Processing of the data may include preparing a replysignal, updating information in memory 100, and/or controlling actuator12 or other external component 10.

When transmitting in the spread-spectrum communication protocol, thedata controller 50 will build a spread-spectrum communication packet (asillustrated in FIG. 4B). The spread-spectrum communication protocol isbuilt by querying the acquisition channels table 105 to find the nextacquisition channel in which to send a preamble of the communicationpacket. Alternatively, the SS chipset 82 may be configured to cyclethrough the designated acquisition channels without having to receive anindex or pointer to a channel from the memory 100. In this alternativeembodiment, the acquisition channel table 105 may be excluded from thememory 100 and stored instead in memory integrated with the SS chipset82. The preamble of the communication packet may also be prepared byquerying the data channel index table 103 to find which data channel tocommunicate the payload portion of the packet. The index to thedesignated data channel is populated within the preamble. The payloadportion of the communication packet is populated and formatted in asimilar manner as the fixed-frequency communication protocol calls for.The communication packet is then passed along to RF transceiver 80 fortransmission.

SS chipset 82 prepares the preamble of the communication packet fortransmission at the designated acquisition channel frequency. Uponcompleting transmission of the preamble, SS chipset 82 then transmitsthe remainder of the communication packet at the frequency designated bythe data channel index. Typically, this requires SS chipset 82 to changefrequency channels mid-communication packet. In some special cases,however, the designated data-channel may be the same as the acquisitionchannel, which is essentially equivalent to the fixed-frequencycommunication protocol.

Importantly, communicating with the two communication protocols alsoprovides the opportunity to communicate in two different modulationschemes. This is beneficial because the drawbacks of each can becountered with the advantages of the other. In one embodiment, thefixed-frequency communication protocol uses an amplitude modulationscheme, such as on-off keying (OOK). The spread-spread communicationprotocol uses a frequency modulation scheme, such as frequencyshift-keying (FSK). These are merely exemplary modulation schemes thatcan be utilized. Those of skill in the art will appreciate that variousmodulation schemes may be utilized. Furthermore, in some embodiments,the two communication protocols may utilize the same modulation scheme.The particular modulation scheme used for each communication protocol byeach transceiver can be remotely controlled by devices in the back-endsystem 21. Control commands can be received downstream to change theparticular modulation scheme to be utilized.

FIG. 3 is an illustration of an embodiment of a preferred frequency band200 at which the dual-mode transceivers communicate. The illustratedfrequency band 200 is the 902-928 MHz band, which falls in the ultrahigh-frequency (UHF) radio band. Other frequency bands may be utilized.The 902-928 MHz band may be advantageous in certain situations becausecommunication ion this band may not require licensing by the FCC,provided signal radiations remain below a given power threshold.

In the embodiment illustrated in FIG. 3, the 902-928 MHz frequency bandis divided into a first set of channels designated as spread-spectrumcommunication channels and a second set of channels designated asfixed-frequency communication channels. The spread-spectrumcommunication channels are further divided into subsets of acquisitionchannels 220 and data channels 210. In the embodiment illustrated inFIG. 3, there are fifty spread-spectrum communication channels, of whichten are designated as acquisition channels 220 and forty are designatedas data channels 210. Each channel comprises 500 kHz, with the carrierfrequency being centered within the 500 kHz.

In other embodiments, the number of spread-spectrum communicationchannels, as well as the number of acquisition channels 220 and datachannels 210 may be different. Furthermore, in some embodiments, theacquisition channels 220 and data channels 210 may overlap. In order tocomply with certain provisions of Part 15 of the FCC's Guidelines forOperation (which is hereby incorporated by reference in its entirety),fifty channels are necessary for spread-spectrum communication.Embodiments of the present invention comply with the FCC's guidelinesfor communicating at a higher power level. By communicating at a higherpower level, longer range communications and/or greater signalpenetrations are possible, which is very advantageous for manyapplications in which system 1 may be utilized.

In one embodiment, the acquisition channels 220 are separated from eachother by four data channels 210, thus providing 2 MHz of bandwidthbetween acquisition channels 220. The acquisition channels 220 arespread evenly across the entire frequency band 200 to spread the powerspectral density across the entire frequency band. Again, this patterncan vary greatly, and should not be limited the embodiments illustratedin FIG. 3. For example, the acquisition channels 220 can be groupedtogether at various sections of the frequency band 200. One mustconsider, however, complying with the FCC's guidelines when designatingthe acquisition channels. The acquisition channels 220 may be evenlyutilized because each transceiver is configured to cycle through theacquisition channels 220, upon transmission, in either a predeterminedand/or pseudorandom pattern. The data channels 210 may also be evenlyutilized because each transceiver is configured to cycle through thedata channels 210 upon transmission in either a predetermined and/orpseudorandom pattern.

The current FCC guidelines require even usage of channels across anentire bandwidth. In one embodiment, it would appear that theacquisition channels 220 would get 4× more usage then the data channels210. This may be accounted for, however, by limiting the data throughputat each acquisition channel 220. The total number of data bitscommunicated in the acquisition channels 220 is about equal to or lessthan the total number of data bits communicated across the many datachannels 210.

Spread-spectrum communication may also be advantageous because itprovides for communication from more devices using a given frequencyband and greatly reduces the effects of interference. If one channel iscurrently in use or has some external interference, the transceivers cansimply switch to another frequency channel. In one embodiment, thetransmitter dictates what the next frequency channel will be bycommunicating the data channel index in the preamble of a communicationpacket. Frequency hopping is often used in spread-spectrumcommunication, which, as its name implies, is generally the process ofchanging frequency channels in which a transceiver communicates duringoperation.

As briefly discussed above with respect to FIG. 2, several embodimentsof the spread-spectrum communication protocol work by communicating apreamble portion of a communication packet in one of the designatedacquisition channels 220. A receiver can cycle through the designatedacquisition channels 220 and lock onto a carrier signal at theacquisition channel 220 in which a transmitter is communicating. Thereceiver then receives the remainder of the preamble, which includes adata channel index field. The receiver then switches to the data channel210 as designated by the data channel index and prepares to receive theremainder (the data portion) of the communication packet. This will bediscussed in further detail in subsequent figures.

The fixed-frequency communication protocol is designated to communicatewithin another frequency band. In the embodiment illustrated in FIG. 3,the fixed-frequency channel band 230 is confined within one of thechannels designated for the spread-spectrum communication protocol. Forexample, as FIG. 3 illustrates, the fixed-frequency channel band 230 isallotted the 916.3-916.7 MHz frequency band which is slightly smallerthen one of the spread-spectrum communication channels of 500 kHz. Itshould be noted that the frequency band selected for the fixed-frequencycommunication protocol is merely a preferred frequency band and otherfrequency bands, including those outside the band dedicated forspread-spectrum communication, could be utilized. Importantly, othercomponents of the dual-mode transceivers are a function of the selectedfrequency band. For example, antenna 60 may be a dual-frequency antennafor operating in two different frequency bands.

In one embodiment, eight channels 235 (each 50 kHz) are dedicated forfixed-frequency communication with the carrier frequency being centeredin each channel 235. Of course, the number of fixed-frequency channels235 and the allotted bandwidth for each channel 235 can vary.

Important to note is the relatively narrow bandwidth provided for thefixed-frequency channels 235. This is because the illustrated embodimentof the fixed-frequency communication protocol calls for lower powercommunication and also amplitude modulation. First, with lower powercommunications, the power spectral density at each carrier frequency ismuch more focussed at the carrier frequency than higher powercommunications. Thus, with higher-power communications, more bandwidthis required to allow sufficient separation between the also-widerfrequency responses. Second, amplitude modulation, such as OOK, does notrequire deviation from the carrier frequency, as only the amplitude ofthe carrier frequency (or a nearby secondary frequency) is beingmodulated.

A receiving device operating within the fixed-frequency communicationprotocol, will search for a carrier frequency by cycling through thefixed-frequency channels 235 searching for a carrier frequency. Oncelocked on to a carrier frequency, the receiver will begin receiving thepreamble and also the data portion of a communication packet. Unlike inthe spread-spectrum communication protocol, the receiver will not berequired to switch to another channel to receive the data portion of thecommunication packet.

FIG. 4A illustrates an embodiment of a fixed-frequency communicationpacket, or frame, 300 and FIG. 4B illustrates an embodiment of aspread-spectrum communication packet 400. Both embodiments preferablyimplement the Manchester encoding scheme. Nonetheless, one of ordinaryskill in the art will appreciate that other embodiments may employ otherencoding schemes. The Manchester encoding scheme is a bit-level encodingscheme well known in the art for its reliability and ease of timingsynchronization. The Manchester encoding scheme translates a binary 1data bit into a low-to-high transition, at the physical layer level. Abinary 0 data bit is thus a high-to-low transition, at the physicallayer level. Thus, for each data bit to be transmitted, a full datacycle is required with a 50% duty cycle. Although this cuts the datathroughput in half, timing and synchronization is easily accomplishedbecause synchronization can be done at each clock cycle.

Referring to FIG. 4A, the fixed-frequency communication packet 300includes a preamble portion 301 and a data portion 302, both of whichare communicated while at the same frequency channel. The preambleportion 301 includes a training sequence 310, which is composed of apredefined sequence of bits. In one embodiment, the sequence 310 is aseries of binary 1s. The length of sequence 310 should be suitable for areceiver to cycle through the designated fixed-frequency channels 235and look for the sequence. The receiver is configured to look for asubset, such as six or eight consecutive binary 1s. If the receiverreceives this subset, the receiver remains at the currentfixed-frequency channel 235. Otherwise, the receiver will move on to thenext channel. In one embodiment, the training sequence 310 is 24 bits inlength. Furthermore, the training sequence 310 could be another sequencebesides consecutive binary 1s. Consecutive binary 0s or alternatingbinary 1s or 0s could be utilized.

As discussed earlier, the Manchester encoding scheme makes timing andsynchronization relatively easy. A string of consecutive binary 1sappears to a receiver to be a square wave with a 50% duty cycle (aswould a string of consecutive 0s, 180 degrees out of phase). If areceiver receives this square wave for a predefined period (equivalentto the prescribed period of time for the synchronization subset), thereceiver will recognize that this data is the start of a communicationpacket, and timing and synchronization can then be performed with astandard phase lock loop.

As illustrated in FIG. 4A, a start marker 320 is composed of two bitsand used to signify the end of the training sequence 310 and the startof the data portion 302 of the communication packet 300. The startmarker 320 breaks away from the standard Manchester encoding scheme andis made up of two full clock cycles (thus two bits) of an all high (oron, for OOK) signal. Certainly, other configurations could be utilized.

The data portion 302 of the fixed-frequency communication packet 300 iscomposed of a variable length payload 330. In one embodiment, thevariable length payload 330 is similar to the variable length payload430 of the spread-spectrum communication packet 400 of FIG. 4B and willbe discussed in further detail below.

Turning now to FIG. 4B, the spread-spectrum communication packet 400 ismade up of a preamble portion 401 and a data portion 402. In oneembodiment, the preamble portion 401 of the spread-spectrumcommunication packet 400 is communicated at one of the acquisitionchannels 220 (See FIG. 3). The preamble portion 401 includes a trainingsequence 410 similar to training sequence 310 and also a data channelindex field 415. In the one embodiment, the training sequence 410 iscomposed of 48 bits, but this may greatly vary in other embodiments. Thelength of the training sequence 410 should be suitable for a receiver tocycle through all of the acquisition channels 220.

The preamble 401 also includes a data channel index field 415, whichcommunicates to a receiver the data channel at which the data portion402 of the communication packet 400 will be communicated. In oneembodiment, the data channel index field 415 is composed of eight bits.The two most significant bits 415 are binary 0s and the remaining sixbits are used to communicate the data channel. The data channel indexfield 415 also serves to notify a receiver that the communication packetis a spread-spectrum communication packet and not a fixed-frequencycommunication packet.

A start marker 420 similar to start marker 320 is then included in thecommunication packet 400. In the embodiment of FIG. 4B, the start marker420 is composed of four bits and used to signify the end of the preamble401.

The data portion 402 of the communication packet 400 is composed of avariable length payload 430. Briefly, the variable length payload 430may include fields, such as a start-of-packet, or header, 431, receiver(Rx) address 432, and transmitter (Tx) address 433. A checksum,cyclic-redundancy check (CRC) 434 or other equivalent error detectionscheme could be included in the variable length payload 430. Next, theactual data is transmitted in a variable length payload 435 followed bya footer 436. In one embodiment, the variable length payload 430 canvary from 112 to 1024 bits. The upper limit is defined by the data rateand a maximum dwell time at a particular channel. These parameters maybe different in other embodiments, thus varying the length of the dataportions of the communication packets. However, the length of the totalcommunication packet should provide for continuous communication at aparticular channel, at a given data rate, that is less then the maximumdwell time allotted by the FCC's guidelines. In one embodiment, 400 msis the maximum dwell time allotted for communication on any frequencychannel in the UHF band. The communication packet has a variable length(but not to exceed a given length) and the preferred data rate is 2400bits per second (bps). This may vary in other embodiments.

The discussion that follows is directed toward the flow charts of FIGS.5-8. The flow charts of FIGS. 5-8 are intended to illustrate embodimentsof methods for communicating in a dual-mode communication protocol. Ingeneral, the methods may be embodied in software, hardware, firmware, orany combination thereof, and may be executed by devices, such as thoseillustrated in the embodiments of FIGS. 1-2.

FIG. 5 is a flow chart illustrating an embodiment of a method 500 fortransmitting in the dual-mode communication mode. Initially, the method500 begins by receiving a command to transmit a particular communicationpacket. The communication packet may be generated by the devicepreparing to transmit, or it may be from another device having just sentthe communication packet. In the latter case, the current device servesas a relay or repeater.

The method 500 proceeds by first searching for the communication mode ofthe intended receiver (step 510). This may be accomplished by examiningthe Rx address of the intended receiver, where information conveying thecommunication mode may be found. For example, the two MSBs of the Rxaddress may be reserved for conveying whether the receiver cancommunicate in the fixed-frequency communication protocol, thespread-spectrum communication protocol, or both. This may requirequerying the Rx address table 104 found in memory 100 of a transceiver(see FIG. 2). Alternatively, this information may be found in anothertable, which is not fully integrated with the Rx address.

If it is determined that the receiver communicates in thefixed-frequency communication protocol (step 515), the transmitter thenbegins transmission of the communication packet in the fixed-frequencycommunication protocol (step 520). The fixed-frequency communicationprotocol operates by communicating the entire communication packet,including the preamble and data portion, while at one frequency channel.Furthermore, the fixed-frequency communication protocol may utilize aparticular modulation scheme, such as a particular amplitude modulationscheme. Likewise, the fixed-frequency communication protocol maytransmit at a given power level. In the preferred embodiment, thefixed-frequency communication protocol operates at a substantiallylow-power radiation level. Other modulation schemes and/or powerradiation levels could be utilized without departing from the scope ofthe present invention.

The transmitter may determine whether the transmission was a success(step 525) by receiving a response from the intended receiver. Incertain instances, a response may not be required, thus the transmittermay not expect such a response. In these instances, success verificationis not necessary and this step may be omitted.

Upon a success, or upon completing transmission of the communicationpacket if success verification is not necessary, the communication modeof the intended receiver may be updated (step 550), if necessary, andthe response communication packet can be processed (step 560). Upon afailure, the method 500 proceeds by attempting to communicate in thespread-spectrum communication protocol (step 530).

Returning back to step 515, if it is determined that the intendedreceiver does not communicate in the fixed-frequency communicationprotocol, the transmitter will then begin transmission in thespread-spectrum communication protocol (step 530). This step will bediscussed in further detail with relation to FIG. 6.

Upon transmitting the communication packet in the spread-spectrumcommunication protocol, the transmitting device may then verify whetherthe transmission was successful by receiving a response from theintended receiver (step 540). If successful, the method 500 proceeds tostep 550 where the communication mode of the intended receiver may beupdated. The transmitter can then process the response, if necessary(step 560). If not successful, the method 500 proceeds by attempting totransmit the communication packet in the fixed-frequency communicationprotocol (step 520).

A simple counter can be applied to count the number of failures orattempts at communicating in the two protocols (step 570). After aprescribed number of failures, a failure mode may be initialized, whichmay include a recalibration feature.

In some situations, the transmitting device may not have knowledge ofthe communication mode in which the intended receiver operates. In thiscase, the default procedure is to first attempt communication in thespread-spectrum communication protocol (step 530). If this issuccessful, the communication mode related to the intended receiver maybe updated. If not successful, transmission can be attempted in thefixed-frequency communication protocol. If successful, the communicationmode related to the intended receiver can be updated accordingly.Alternatively, the default may be to attempt communication first in thefixed-frequency communication protocol, and then the spread-spectrumcommunication protocol.

FIG. 6 is a flow chart illustrating an embodiment of a method 530 fortransmitting in the spread-spectrum communication protocol. The method530 begins by placing the transmitting device in the spread-spectrummodulation mode (step 531). In one embodiment, the spread-spectrummodulation mode utilizes a frequency modulation scheme, such asfrequency shift keying (FSK) modulation. In other embodiments, othermodulation schemes could be utilized, including those other thenfrequency modulation schemes. Furthermore, the spread-spectrumcommunication protocol calls for transmitting at a relativelyhigher-power radiation power then the fixed-frequency communicationprotocol. In this manner, the spread-spectrum communication protocolfacilitates greater range and signal penetration.

The method 530 proceeds by setting the transmitting channel to thedesired acquisition channel (step 532). The desired acquisition channelmay be chosen in a predetermined pattern, or randomly.

Once the transmitting channel is set, the preamble of the communicationpacket can be sent (step 533). This step includes sending the trainingsequence (step 534) and the data channel index (step 535).

Upon sending the preamble, the transmitting device then switches thetransmitting channel to the data channel as designated by the datachannel index (step 536). The designated data channel may be selected ina predetermined pattern, or randomly. Subsequently, the data portion ofthe communication packet (step 537) is sent.

Once the entire communication packet is sent, the transmitting devicemay then switch to receive mode and await a response acknowledgingreception of the communication packet by the intended receiver (step538). This step may be omitted if no response is necessary. Receive modeis described in further detail in subsequent figures.

FIG. 7 is a flow chart illustrating one embodiment of a method 600 forreceiving in the dual-mode communication protocol. The method 600 beginsby placing the receiving device in one of the communication modes, inthis case the spread-spectrum communication mode, which includes settingthe demodulation mode to the chosen spread-spectrummodulation/demodulation scheme, as discussed in FIGS. 5 & 6 (step 605).

Next, the receiving channel is set for the next acquisition channel inthe sequence or series of acquisition channels (step 610). The sequenceor series of acquisition channels may be predetermined and preprogrammedinto the firmware of the receiving devices, or may be done in a randomor pseudorandom fashion. If it is determined that all of the acquisitionchannels have been used without detecting a carrier signal (step 615)the method 600 then proceeds with switching to fixed-frequencycommunication mode, which will be discussed shortly.

At each acquisition channel, a carrier signal is checked for usingstandard carrier detection techniques as known in the art (step 620). Ifone is not found at the current acquisition channel, the method 600returns to step 610, where the receiving channel moves on to the nextacquisition channel.

If a carrier signal is detected, the method 600 proceeds with receivingthe communication packet in the spread-spectrum communication protocol(step 630), which is discussed in further detail in FIG. 8.

Next, the receiving device transmits a response back to the originatingtransmitter verifying a successful communication (step 640).Transmitting a successful response may require communicating by way ofthe methods illustrated in FIGS. 5 & 6. Upon transmitting a response,the receiving device can then return back to the start of the method 600and prepare for the next communication packet.

As mentioned above, if all of the acquisition channels are cycledthrough and a carrier signal is not detected (at step 615), the method600 proceeds to the fixed-frequency communication mode. In this case,the receiving device switches (if necessary) to the fixed-frequencydemodulation scheme (step 645). In one embodiment, the fixed-frequencymodulation/demodulation scheme is different from the spread-spectrummodulation scheme, thus requiring a switch. Alternatively, however, thetwo modulation/demodulation schemes may be the same.

Next, the receiving channel is set to the next fixed-frequency channel(step 650). The next fixed-frequency channel may be selected among thedesignated fixed-frequency channels at random or in a predeterminedmanner. If it is determined that all of the fixed-frequency channelshave been traversed without detecting a carrier signal (step 655), arecalibration procedure may be initiated (step 685). The recalibrationprocedure may not, however, be initiated until after a significantnumber of traversals of the acquisition channels and fixed-frequencychannels without a carrier signal detection.

If a carrier signal is detected at step 660, the receiving device lockson and synchronizes communication by receiving the training sequence inthe preamble of the communication packet. The remainder of thecommunication packet, including the data portion is then received at thecurrent receiving channel (step 670).

Included within the step of receiving the entire communication packet(step 670) are several points at which the integrity of the data isverified. First, the receiving device receives the preamble of thecommunication packet (step 671). Next, the preamble is verified todetermine whether it is a valid preamble (step 672). If not, the method600 may return to step 650 where a new fixed-frequency channel isselected. If a valid preamble is detected, the receiving device receivesand verifies the remainder of the communication packet (step 673). Ifthe communication packet is invalid, it may be ignored and the methodresumes back to step 650. If the communication packet is valid, thereceiving device may then switch to transmission mode and transmit aresponse (step 680).

The recalibration procedure (step 685) may greatly vary with otherembodiments. In one embodiment, particular environment conditions can beverified to determine whether drastic changes have occurred which couldresult in device malfunctions (step 686). For example, drastic operatingtemperature changes or ambient temperature changes could be verified todetermine whether they are the cause of a possible device malfunction.In practice, environmental conditions such as these take time to change,thus the recalibration procedure may be performed at certain intervalsof time, perhaps every 1000 fixed-frequency channel cycles, as anexample. If recalibration is necessary (step 687), a recalibrationprotocol could be enabled (step 688).

The method 600 may return back to the spread-spectrum communication modeat step 605. In other embodiments, it is entirely foreseeable that thefixed-frequency communication mode is the first mode chosen, as opposedto the spread-spectrum communication mode. In this case, a receivingdevice would first attempt to receive in the fixed-frequencycommunication mode and then switch to the spread-spectrum communicationmode after cycling through all of the fixed-frequency channels.

FIG. 8 is a flow chart illustrating an embodiment of a method 630 forreceiving in the spread-spectrum communication protocol. The method 630begins once a carrier signal has been detected at a particularacquisition channel. A receiving device then receives a preamble portionof a communication packet, which includes a training sequence and datachannel index (step 631). The training sequence, as discussed earlier,is used to synchronize the timing for the receiving device.

Once the preamble is received, the receiving device may verify whetherthe preamble is valid (step 632). If not, the receiving device mayreturn back to step 610 and switch to the next acquisition channel.

If the preamble is valid, the method 630 proceeds with looking up thedata channel corresponding to the received data channel index in thepreamble (step 633). Once established, the receiving device switches tothe designated data channel, if necessary (step 634). In certaininstances, where the acquisition channels and data channels overlap, itmay be possible for the data channel index to indicate to the receivingdevice to remain at the current channel for data reception. For example,the special case of six binary 1s may indicate to the receiving deviceto remain at the current acquisition channel for data reception.

The data portion of the communication packet is then received andverified for integrity (step 635). If the communication packet is foundto be invalid, the receiving device may revert back to step 610 wherethe next acquisition channel is selected. If the communication packet isfound to be valid, method 630 ends, and the receiving device prepares totransmit a response, if necessary.

The embodiment or embodiments discussed were chosen and described toillustrate the principles of the invention and its practical applicationto enable one of ordinary skill in the art to utilize the invention invarious embodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth to which they are fairlyand legally entitled.

1. A system for monitoring and controlling remote devices, said systemcomprising: a first, a second and a third remote devices; a first, asecond and a third wireless transceivers integrated with said respectiveremote devices, wherein said wireless transceivers are configured tocommunicate with at least one of a spread-spectrum communicationprotocol and a fixed-frequency communication protocol; the firstwireless transceiver and the third wireless transceivers each comprisinga logic element configured to: transmit or receive a first portion of acommunication frame at a first frequency channel, wherein the firstportion of the communication frame comprises a data channel index thatindicates a second frequency channel; switch to the second frequencychannel; transmit or receive a second portion of the communication frameat the second frequency channel; the first wireless transceiver isconfigured to switch between communicating in said spread spectrumcommunication protocol and said fixed frequency communication protocolsaid communication protocols by determining if after traversing througha first set of designated channels for communicating in one of saidcommunication protocols and not receiving a communication frame in oneof said designated channels; and the first wireless transceiver and thesecond wireless transceiver are configured to communicate in thefixed-frequency communication protocol by transmitting or receiving apreamble and data portion of a communication frame at a third frequencychannel.
 2. The system of claim 1, wherein said wireless transceiversare further configured to communicate with a first modulation schemewhen communicating in said spread-spectrum communication protocol and tocommunicate with a second modulation scheme when communicating in saidfixed-frequency communication protocol.
 3. The system of claim 2,wherein said first modulation scheme is the same as the secondmodulation scheme.
 4. The system of claim 2, wherein said firstmodulation scheme is a frequency modulation scheme.
 5. The system ofclaim 2, wherein said second modulation scheme is an amplitudemodulation scheme.
 6. The system of claim 1, wherein said wirelesstransceivers are further configured to communicate at a firstradiating-power level when communicating in said spread-spectrumcommunication protocol and to communicate at a second radiating-powerlevel when communicating in said fixed-frequency communication protocol.7. The system of claim 6, wherein said first radiating-power level ishigher then said second radiating-power level.
 8. The system of claim 1,wherein said first and second remote devices are utility meters, andwherein said wireless transceivers are configured to communicate atleast data corresponding to the measurements made by said utilitymeters.
 9. The system of claim 1, further comprising: a local areanetwork (LAN) of wireless transceivers, wherein said first and secondwireless transceivers are part of said LAN; and at least a first gatewayin communication with said LAN.
 10. The system of claim 9, furthercomprising: a back-end system in communication with said at least firstgateway via a wide area network (WAN), such that data is passed fromeach wireless transceiver in said LAN to said back-end system via saidat least first gateway and WAN.
 11. The system of claim 10, wherein saidback-end system comprises: a network server configured to remotelycontrol communication functions of said wireless transceivers in saidLAN.
 12. The system of claim 11, wherein said network server isconfigured to remotely control a modulation scheme in which any of saidwireless transceivers communicate in either communication protocol. 13.The system of claim 11, wherein said network server is configured toremotely control a radiating-power level at which any of said wirelesstransceivers communicate in either communication protocol.
 14. A systemfor monitoring the utility consumption measured by a plurality ofutility meters, said system comprising: a plurality of utility meters; anetwork of wireless RF transceivers for communicating utilityconsumption data, wherein said network of wireless RF transceiverscomprises a first dual-mode transceiver, a first fixed-frequencytransceiver, and a first spread-spectrum transceiver; the firstspread-spectrum transceiver and first dual-mode transceiver each havinga data channel index table stored on a memory element, the data channelindex table correlating a plurality of data channel indexes to aplurality of data channel frequencies; the first spread-spectrumtransceiver and the first dual-mode transceiver each having a logicelement for communicating in a spread spectrum protocol over a pluralityof acquisition channel frequencies and a plurality of data channelfrequencies, the logic element configured to: prepare a communicationmessage having a preamble portion and a separate data portion; determinean acquisition channel frequency to transmit the preamble portion and adata channel frequency to transmit the data portion; insert into thepreamble portion a data channel index corresponding to the data channelfrequency; transmit the preamble portion over the acquisition channelfrequency and transmit the data portion over the data channel frequency;receive the preamble portion over the acquisition channel frequency;ascertain the data channel frequency by comparing the data channel indexin the preamble portion to the data channel index table stored inmemory; and receive the data portion by switching reception to the datachannel frequency ascertained from the data channel index; the firstdual-mode transceiver is configured to switch between communicating in afixed-frequency communication protocol or said spread spectrumcommunication protocol by determining if after traversing through afirst set of designated channels for communicating in said spreadspectrum communication protocols and not receiving a communication framein one of said designated channels; the first fixed-frequencytransceiver and the first dual-mode transceiver are configured tocommunicate in a fixed-frequency communication protocol by transmittingor receiving a preamble and data portion of a communication frame at athird frequency channel; a first gateway in communication with eachwireless RF transceiver either directly or via other wireless RFtransceivers, the first gateway relaying data from said network ofwireless RF transceivers to a back-end system; the first gatewayconfigured to recover the data channel index from the preamble of thefirst portion of the communication frame and switch to a data channelfrequency designated by the data channel index to receive the dataportion of the communication frame.
 15. The system of claim 14, whereina first portion of said network of wireless RF transceivers areintegrated with individual ones of said plurality of utility meters anda second portion of said network of wireless RF transceivers arestand-alone RF transceivers.
 16. The system of claim 14, wherein said atleast first gateway is a dual-mode gateway and is configured tocommunicate in the fixed-frequency communication protocol or thespread-spectrum communication protocol, depending on the protocol inwhich an intended transceiver communicates.